Christ looks at us, his eyes pools of mystery in a golden face; his hair long, glowing and curled; his right hand elegantly touching his... fur coat?

Coming closer, you realise the painting is not Christ after all. It is Self-Portrait at 28 by Albrecht Dürer. The Renaissance master has given himself the appearance of a transfigured, charismatic living god. There's no doubting the conscious quotation of the conventional image of Jesus. No doubting either the advanced aesthetic of this painting done in about 1500.

Dürer, who made two trips to Venice in his lifetime, explores here the same rhapsodic, full-frontal sensuality as the Venetian Giovanni Bellini - who was to become Dürer's friend - brought to his paintings of the dead Christ. Dürer was one of his own favourite subjects. He found himself amazing. He portrayed himself in fine clothes, not as a simple German craftsman like his father, a goldsmith in Nuremberg, but as a glamorous international artist, a man of style and sophistication.

He was inordinately proud of that long hair. It flows, coiled and bright, from under a floppy black-and-white cap in his 1498 self-portrait in the Prado. And in a drawing that can be seen in the forthcoming exhibition of Dürer's graphic art at the British Museum, he portrayed himself at the age of 13, precocious not just in talent but in pride, his hair hanging freely.

But there is more than vanity to Dürer's self-portraits. From an early moment in his life, he was aware of himself as a genius, as an inspired creator. One interpretation of his Christ-like self-portrait is that it champions the artist as demiurge, possessing divine power to create worlds. Dürer came to be recognised - even by the grudging Italians - for a mighty flow of ideas and images.

The 16th-century Florentine art chronicler Giorgio Vasari, though sniping at his style, had to praise his "extravagant imagination", and acknowledged that designers and painters all over Europe "have since availed themselves of the vast abundance of his beautiful fantasies and inventions". The distorted, psychoerotic figurings of mannerist artists, the fantastic heroic visions of the baroque and, beyond that, 20th-century surrealism, delved happily into Dürer's imagination.

And yet that fecundity was poised on a cusp between the middle ages and the Renaissance. Dürer was a learned and progressive man, a humanist intellectual, credited in his lifetime with bringing the proportion and perspective of the Italian Renaissance to northern Europe.

The same taste for the latest fashion that made him such a clothes horse made him long to be intellectually up to date. Together with his best friend, the Nuremberg intellectual Willibrand Pirckheimer, he explored topics from Egyptian hieroglyphs to the humanist theology of Erasmus. In 1506, during his second stay in Venice, he wrote excitedly to Pirckheimer that he was about to "ride to Bologna where someone is willing to teach me the secrets of perspective". No one knows who this scientific deep throat was, but Dürer learnt well; he wrote influential books on perspective, human proportion and geometry.

His role model was Leonardo da Vinci. Dürer was aware of many of Leonardo's works, including apparently The Last Supper, and definitely Leonardo's studies for the equestrian monument to Francesco Sforza in Milan.

Most of all, though, Dürer understood the sum of Leonardo's parts, at once craftsman, scientist and humanist intellectual. More than anyone else except Michelangelo, Dürer took up the challenge of the supreme Renaissance mind. And yet the sublime energies that Dürer's art channels are not those of a solitary mind but of an entire culture, and one that was anything but modern.

Dürer might have wanted to be recognised as a theorist and a handsome man, but he was best known as a fantastic visionary of gothic excess. When Vasari praised his "extravagant imagination" he was referring to a specific work: Dürer's woodcut Apocalypse, published in 1498. This savage yet sophisticated work, executed in a very large format alternating 15 prints by Dürer with the text of The Apocalypse of St John, transfixed the European imagination, uniting backwoods, superstitious Germans and urbane Italians alike in their awe at Dürer's Four Horsemen riding machine-like over the earth, blind and dispassionate, crushing burghers beneath them.

Graphic art - drawings, woodcuts, engravings - is where Dürer's imagination is at its most fantastical. That is why the exhibition at the British Museum is one everybody should see. Printmaking was the necessary medium of German popular culture just as it was the essential, international conduit of Renaissance iconography and ideas. It was a hybrid offspring of the printing press. The invention of printing proliferated the word - and made it possible to reproduce the image. Woodcuts in particular could be cheap, and everyone could see them, nailed up at inns, sold by wandering hawkers.

Dürer was perhaps the first to realise the freedom this mass medium offered the artist: he could design, publish and sell his own woodcuts and engravings. That is, he could be what that self-portrait as a god wants the artist to be - an untrammelled creator, a divine fount of images.

Dürer's printed images tap into the new knowledge he got from Renaissance Italy - not just perspective but the rediscovery of the classical nude and pagan myth - and fuse it with older, lower sources, making an art that deploys Renaissance aesthetics to some pretty populist ends.

The print The Sea Monster might look like a classical myth, an illustration of Ovid. It depicts a swimming, bearded male figure - like a Triton, except that in addition to a scaly body he has antlers - abducting a nude woman who doesn't seem too bothered; she poses Venus-like on his back, while the people from the walled town on shore scream and wave their arms impotently.

It is a troubling, wondrous image of the erotic; Dürer's art is very sexual. But it has nothing to do with classical myth. It almost certainly illustrates a sensational news story of the time: a series of women on the Adriatic coast of Italy were abducted by a sea monster. Finally it was killed and put on display at Ferrara.

Dürer was an accurate, loving student of nature; his art is full of meticulous, captivating depictions of vegetation, animals, even a clod of earth. His landscape drawings, such as Landscape with an Alpine Pool (c 1495-6) can easily be mistaken for 19th-century watercolours. He drew and made prints of animals of all kinds: a walrus, a lion, a rhinoceros.

Yet his inexhaustible ingenuity always came back to universal human images, to expressive metaphors for the anguish of existence. There is no image that quite communicates anxiety like Dürer's Knight, Death and Devil (1513). An armoured knight rides through a deep, tenebrous German forest; he is miles from home, from the distant castle on a hill, and in the creeping shadows, nightmares attack him. Death, with snakes sprouting from his rancid face, holds up an hourglass; the devil, a nauseating monstrosity, walks behind.

The knight does not flinch; he doesn't look at the spectres. He rides on, his horse - derived from Leonardo's drawings for the Sforza monument - equally determined, as is his hound. This has been interpreted as a Christian allegory - the soul, armoured against fear, refusing even to see the demons in the dark as he rides towards his final goal. And yet even without that allegory, it is a universal, true image of the imagination producing horrors.

But Dürer is not the knight riding fearlessly through the forest, ignoring the monsters of death and sin; his job was not to avert his eyes. He must look. Nor is he St Jerome in his Study, the perfect Christian scholar that Dürer engraved in 1514 - the second in the great trinity of prints, beginning with the knight in the forest, that are the peak of Dürer's graphic art. No, the image that, as the great art historian Erwin Panofsky argued, must be seen as Dürer's supreme self-portrait is the brooding, winged female genius who sits desolate and aimless amid an unfinished architecture, overlooking an empty nocturnal sea lit by a comet, in his 1514 print Melencolia I.

Imagination, for Dürer, was not a simple gift: it was also a curse. If he begins with an impudent self-image as a 13-year-old draughtsman, and comes to see himself as a Christ-like visionary, Dürer's most powerful image of genius is troubled and troubling.

The title, Melencolia I, is engraved on the wings of a bat, a creature associated with night fears; even Melencolia's dog, usually an emblem of loyal energy, shares her disconsolate, down-at-heel wistfulness. It is slyly comic. While sanguine, choleric and phlegmatic types get on with their lives, as dictated by the medieval theory of the four temperaments, Melencolia just sits and thinks. Thinks pointlessly, hopelessly. Imagination gone mad, fantasy run to seed. Around her are scattered a chaotic variety of tools: geometrical instruments, pens, a bellows. On her head is a pathetic wreath of watercress to moisten her dry spirits. She has wings she doesn't use. She has a set of compasses she holds limply.

Melencolia I is a revolutionary declaration of the mysterious, ambiguous nature of the psyche, and the heroic suffering of introspection. If to think is to be melancholy, to be melancholy is to think. Widely disseminated, it created a new archetype, that of inspired and creative melancholy, the introspective, uncontained imagination. Portraits gave their sitters the troubled eyes and cheek-resting-on-hand pose of Melencolia I; melancholy became a fashion. It was the beginning of modern subjectivity.

The brightness of Dürer's sharp Renaissance drawing drags with it a melancholic medieval ghost. His eyes may be on the bright sights of Venice but his soul is in the northern woods. And it is in that realm of magic, the occult, apocalyptic fantasy and religious terror that Dürer finds images welling up into his brain. Melencolia is, for this artist, the condition of genius; it is what goes with thought and creativity. Only from long, lonely nights of febrile thinking - like Melencolia's - will anything new be created in the world. Out of his melancholy he brought forth miracles. If any artist in history had the right to see himself as the Messiah it was Albrecht Dürer.

· Albrecht Dürer and His Legacy: The Graphic Work of a Renaissance Artist is at the British Museum, London WC1, from Thursday. Details: 020-7323 8000.

About this article

Albrecht Dürer: Divine inspiration

This article appeared on p18 of the Guardian review section of the Guardian
on Friday 29 November 2002.
It was published on
the Guardian website
at 12.59 EST on Saturday 30 November 2002.
It was last modified at 12.59 EDT on Monday 7 April 2003.
It was first published at 12.59 EDT on Monday 7 April 2003.